08 Tacoma misfire on cylinder 2

Ok guys, need some advice. I have an 08 Tacoma 4.0 reading misfire on cylinder 2. Truck shakes and loses power when accelerating. Typically, after it warms up. Here’s what I’ve done thus far. Coil packs, spark plugs, cam sensors, crankshaft position sensor, mass air flow sensor, compression test, injectors, and as of tomorrow all connectors on both coil packs and injectors as well as installing a new variable timing valve sensor. I’ve also treated the fuel, oil and coolants. I have compression and as far as I can tell no blown head gasket. Is it my timing chains? Also, while we are on the subject, I have no issues with my 4X4. But, I have an air line hanging down at the back of my transfer case and it appears to have been hanging there awhile. There is a plastic black nipple that it looks to have attached to possibly but with the line split and dry rotted it would have to be replaced before reconnecting if that is indeed where it goes. Any insight as to whether this breather line should be replaced and connected or not.

 

Welcome to TW forums.

Mileage on the truck?
First owner, or are you the second / third owner? Maintenance history (approximately)? Oil change interval?
Have you checked both the VVT valves for damage and/or excessive build up (left & right bank) and their filter screens as well?

 

All of this for a single cylinder misfire?!
Has it always been cylinder 2?
Do you only have a P0302 code or other codes like P0352 or P0300?

That is the vent for the Transfer Case Actuator, fix it ASAP so you don't get dirt and moisture in the actuator.
https://www.tacomaworld.com/threads/4wd-system-operation-help-thread.742420/#post-26430333

 

Replaced parts oem or aftermarket?

 

Truck has 185k on it. Just bought it 2 weeks ago. Drove fine until I decided to accelerate one day to pass a vehicle and that’s when it all started. Multiple owners and no idea about previous maintenance. Oil changed 2 weeks ago. The reason for all of the things is because I was going through the process of elimination starting from plugs and so on. I have checked the vvt valves. Both had build up which is why I’m replacing them tomorrow. Filters were clean. For the most part it has just been cylinder 2. At one point it changed to cylinders 1-2 and multiple cylinders but since then it has went back to just cylinder 2.

I will fix the air line tomorrow as well, thank you for that.

replacing with all oem parts

 

I'd fix this first. Find out where it is supposed to be. It may be a vacuum line that is causing all your issues.

 

1 I'd get an obd reader on it to see what codes are there. Write them down, use the erase function, see what comes back.

2 test if that cylinder is getting a spark.

What were the compression readings?

 

P0302 has been the main code. At one point I was getting a p0301 and a p0300. But the main consistent code has always been p0302. I have erased it every time I did a new part to reset and see. I’m using a Autel scanner. Compression readings were 160ish. The vacuum hose has been off a long time. It’s split and dry rotted. I have spark.

 

What are your fuel trims?
Short and Long, that can help point you in one direction.
Lean? Rich?

More specifically Bank 1.
But give use Bank 2 as well.

 

It’s not a vacuum line, it’s a vent line. This will happen to all Tacoma 4x4s eventually if not caught early. There’s some stress on the vent line due to a relatively sharp 180° turn it makes, so it goes bad faster than other connections that don’t have that stress on them. Mine was on its way out, but I was able to snip off the last inch or so and add a 90 degree elbow with a short section of new vacuum line. This takes some of the bend out of it.

As @TnShooter said, the transfer case actuator that it connects to will often go bad due to water intrusion when this happens. Since the OP bought the truck only recently, it has probably been off for a while, and he should plan on replacing the actuator at some point before it causes him trouble way the hell up some fire trail. But it isn’t related to his misfire issue, there’s no engine vacuum in that line.

 

I’ll have to Google fuel trims, not familiar with that.

 

If your scanner has something called a freeze frame option under the code. Post up the data.

 

https://gtc.ca/blog/long-term-fuel-trim-and-short-trim-fuel-trim/

 

I'm not hijacking just letting you know that I am having the same issue with my 2015 TRD pro. For the last 5 months actually. Ran it hard one day to get fuel, filled it up and then 3 min down the road....P0300. Mine is mainly P0302 as well but will travel up bank 2.

I have replaced everything you have as well since I bought mine used. Toyota techs charged me 800 to tell me to reinstall the SAIS system which I'm not doing because it ran fine before this.

Today I'm going to try and swap out my AFR sensors as my fuel trims are inversely proportional to each other right before I get the misfire on my live scans and see if the problem shifts to bank 1. There were times I would get all 6 cylinders (CEL) but I wasn't live scanning I think that's due to all of bank 2 misfiring which throws the whole engine out.

I have also performed an exhaust back pressure test on Bank 2 up and downstream and it came back clear.

When I replaced injectors, number 2 had carbon on the nozzel.

 

I just drove it today after swapping AFR's, same thing. Random misfires with cylinder 2 being the main one per my live scan and B1 and B2 fuel trims operating inversely of each other. Have you had any luck with yours OP?